Freescale MC34844 10路LED电视背光驱动解决方案
Freescale公司的 MC34844/A 是集成了电源的10路LED背光驱动器，工作电压7.0-28V，能驱动160个10路并联的LED串。每串的电流匹配在±2%内，可通过I2C/SM总线接口进行编程。LED亮度调光256级，可编程到65,000:1 (256:1 PWM, 256:1 电流 DAC)，集成的DC/DC转换器效率为90%，MC34844每路LED电流多达50mA，MC34844A每路LED电流多达80mA，主要用在宽达43吋HDTV，笔记本电脑，GPS屏等。本文介绍了MC34844/A主要特性，方框图，多种应用电路以及KIT34844AEPEVBE评估板主要特性，电路图和材料清单。
10 Channel LED Backlight Driver with Integrated Power Supply
The 34844/A is a high efficiency, LED driver for use in backlighting LCD displays from 10" to 20"+. Operating from supplies of 7.0 to 28 V, the MC34844/A is capable of driving up to 160 LEDs in 10 parallel strings. Current in the 10 strings is matched to within ±2%, and can be programmed via the I2C/SM Bus interface.
The 34844/A also includes a Pulse Width Monitor (PWM) generator for LED dimming. The LEDs can be dimmed to one of 256 levels, programmed through the I2C/SM Bus interface. Up to 65,000:1 (256:1 PWM, 256:1 Current DAC) dimming ratio.
The integrated boost converter generates the minimum output voltage required to keep all LEDs illuminated with the selected current, providing the highest efficiency possible.
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